1. Technical Field
The present invention relates to novel cyclohexane-1,3-dione derivatives of the following formula (I) useful as herbicides and plant-growth regulants. ##STR2## wherein, X is selected from the group consisting of hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkoxy, halogen, C.sub.1 -C.sub.6 haloalkyl, nitro, cyano, C.sub.1 -C.sub.6 alkylthio, C.sub.1 -C.sub.6 alkylsulfinyl, C.sub.1 -C.sub.6 alkylsulfonyl, sulfamoyl, N-(C.sub.1 -C.sub.6 alkyl) sulfamoyl and N,N-di(C.sub.1 -C.sub.6 alkyl) sulfamoyl group;
(X)n represents number of X substituents which may be the same or different on benzene ring, where n is 1, 2 or 3. PA1 R.sup.1 is selected from hydrogen and C.sub.1 -C.sub.4 alkyl group; PA1 R.sup.2 is selected from C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl and C.sub.2 -C.sub.6 alkynyl group; PA1 R.sup.3 is selected from hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 haloalkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 haloalkenyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.2 -C.sub.6 alkylthioalkyl, benzyl and C.sub.2 -C.sub.6 haloalkanoyl group; PA1 R.sup.4 is selected from hydrogen, alkali metal cation, alkaline earth metal cation, C.sub.1 -C.sub.4 alkanoyl, C.sub.1 -C.sub.4 haloalkanoyl and benzoyl group.
Also, cyclohexyl moiety, one of the substituents on benzofuran ring, is substituted at 4, 5, 6 or 7 position. The (X)n can't be filled only with hydrogens and the (X)n can substitute position where cyclohexyl moiety is not substituted;
2. Description of the Related Art
Cyclohexane-1,3-dione derivatives and their herbicidal activity were already known in the art. For example, Alloxidim-sodium (Australian Patent No. 464,655; United Kingdom Patent No. 1,461,170; U.S. Pat. No. 3,950,420) and Sethoxydim (Germany Patent No. 2,822,304) have come into the market as grass herbicides. Cyclohexane-1,3-dione derivatives having phenyl substituent (U.S. Pat. No. 4,511,391, U.S. Pat. No. 4,639,267 and U.S. Pat. No. 4,652,303) which have similar structure to our invention has been known. This present invention differs from the compounds having 2,3-dihydrobenzofurans disclosed in U.S. Pat. No. 4,511,391, in which 2-position of benzofurans were claimed only as methylene group.
In addition, the benzofuran moieties in the present invention can not be synthesized by the methods of the synthesis of the benzofurans disclosed in U.S. Pat. No. 4,511,391. The compounds in the present invention showed good rice tolerance, while the compound in the U.S. Pat. No. 4,511,391 showed not.
Furthermore a part of compounds developed by these inventors similar to the above formula (I) but differ in substituent of (X)n on benzene ring.
Therefore, with consideration as to the aforesaid points the present inventors have made efforts to develop new herbicidal compounds which have powerful herbicidal activity and good selectivity, especially useful for selective control barnyardgrass species in upland and paddy rice.